NO315233B1 - Drugs of paclitaxel derivatives - Google Patents

Abstract

Palcitaxel derivatives having antitumor properties have the formula (I), or a pharmaceutically acceptable salt thereof. where, among others. a. Rer -CO (0) R; Rer hydroxy; R 2 is hydrogen; R is hydroxy or -OC (O) R; R 6 is methyl, 6 and R 6 are hydrogen; Rs is -OC (0) R; Rog R7 together form an oxo group; R 6 is independently C 1-4 alkyl, C 1-4 alkenyl or -Z-Rh wherein Z is a direct bond or C 1-4 alkyl and R 11 is aryl, substituted aryl C 1-8 cycloalkyl or heteroaryl; p is 0; Rd and Re are hydrogen; Rf is hydrogen, Rx is C1-cycloalkyl, C-alkenyl or C1-4alkyl, all of which are optionally substituted by from 1 to 6 identical or different halogen atoms, or Rx is a radical of the formula. wherein D is a bond or C 1-4 alkyl, and Ra, Rog R ° are independently hydrogen ,. nitro, amino, C - alkylamino, di C - alkylamino, halogen, C - alkyl or C - alkoxy. Pharmaceutical preparations containing paclitaxel derivatives and the use of the derivatives are also mentioned.

Description

The present invention relates to a chemical compound, as well as a pharmaceutical preparation and use of the chemical compound for inhibiting tumor growth in mammals. More specifically, the invention relates to paclitaxel derivatives, pharmaceutical preparations thereof, and their use as antitumor agents.

Taxol® (paclitaxel) is a natural product extracted from the bark of Pacific yew, Taxus brevifolia. It has been shown to have excellent antitumor activity in animal models in vivo, and subsequent investigations have clarified a unique mode of action involving abnormal polymerization of tubulin and interruption of mitosis. It has recently been approved for the treatment of stubborn, advanced ovarian cancer and breast cancer, and investigations involving other types of cancer have shown promising results. The results of clinical trials of paclitaxel are given by numerous authors, such as Rowinsky and Donehower in "The Clinical Pharmacology and Use of Antimicrotubule Agents in Cancer Chemotherapeutics", Pharmac. Ther., vol. 52, 1991, pp. 35-84; Spencer and Faulds in "Paclitaxel, A Review of its Pharmacodynamic and Pharmacokinetic Properties and Therapeutic Potential in the Treatment of Cancer", Drugs, vol. 48 (5), 1994, pp. 794-847; wounded by K.C. Nicolaou et al. in "Chemistry and Biology Taxol", Angew. Chem., Int.Ed. English, vol. 33, 1994, p. 15-44, as well as in the publications cited therein.

currently clinical trials in Europe and the USA. The structures of paclitaxel and Taxotere® are shown below together with the conventional numbering system for molecules belonging to this class. Such a numbering system is also used in this application.

Taxol® : R Ph; R' = acetyl

Taxotere®: R = tert-butoxy; R<1> = hydrogen

One disadvantage of paclitaxel is its very limited water solubility, necessitating its formulation in non-aqueous pharmaceutical vehicles. The commonly used carrier is "Cremophor EL", which itself has unwanted side effects in humans. Consequently, several experimental teams have prepared water-insoluble derivatives of paclitaxel, some of which are described in the following publications:

(a) US Patent 4,942,184; (b) US Patent 5,059,699; (c) US Patent 4,960,790; (d) European Patent Application 0,588,959 Al, published September 8, 1993; (e) Vyas et al., Bi porganic s Medicinal Chemistrv T.^ f. tprs. Vol. 3, '1993, ?. 1357-1360, (f) Nicoiaou et al., Nature, vol. 364, 1993, p.

464-466;

(g) European patent application 0,604,910 t published

6 July 1994.

The compounds according to the present invention are water-soluble phosphonooxymethylcarbamate derivatives of paclitaxel, as well as pharmaceutically acceptable salts thereof. The water solubility of the salts facilitates the manufacture of pharmaceutical preparations.

The antitumor compounds according to the invention are characterized by having the formula I, or pharmaceutically acceptable salts thereof

where

Ri is hydroxy, -CO(0)R<x> or -0C(0)0R<x>,

R<2> is hydrogen, hydroxy, -OC(0)R<K> or -OC(0)0R<*>, r2' is hydrogen, hydroxy or fluorine,

r<6>' hydrogen or hydroxy,

r<6> is hydrogen, or R<2> and R° can together form an oxirane ring or a bond,

r<3> is hydrogen, hydroxy, C1_$-alkyloxy, -OCONR^R<3-2 >, -OC(0)R<x> or -OC(0)0R<x>,

r<8> is methyl or hydroxymethyl, or R<&> and R^ can together form a cyclopropane ring,

R<9> is hydroxy or -OC(0)R<x>,

under the conditions that R^ and R^ form a cyclopropane ring, R-<1> is hydrogen; when R- and R° form an oxirane ring or double bond, r<2->' and ' are hydrogen; when R<2> is hydroxy, -OC(0)R<x> or -OC(0)OR<K> R<2>' is hydrogen; and when r<2*> sr fluorine, R^ is hydrogen,

one of R<7> and R<7>' is hydrogen and the other is hydroxy, -OC(0)R<x> or -OC(0)OR<x>,' or R<7> and R< 7>' can together form an oxo group,

R1 and R12 are independently C1-5-alkyl, hydrogen, aryl or substituted aryl,

bA and r5 are independently C1-5 alkyl, C2-6 alkenyl, C2-6 alkynyl or -Z-R<1>^, where Z is a direct bond, C1-6 alkyl or C2-6 alkenyl, and R 2 O is aryl, substituted aryl, C 5 -g cycloalkyl or heteroaryl,

p is 0 or 1,

R d and R e are independently hydrogen, C 1 -C 8 alkyl, aryl, substituted aryl or phosphonoprotecting group,

RE is hydrogen or hydroxy,

Rx is <C>3-6-cycloalkyl, C2-6"alkeny1 or C1-6-alkyl, all of which are optionally substituted with from 1 to 6 identical or different halogen atoms, or Rx is a radical of the formula

where

D is a bond or C1-6 alkyl, and

Ra, RD and R<c> independently of one another are hydrogen, nitro, amino, C1-6-alkylamino or di-C1-6-alkylamino, halogen, C1-6-alkyl, hydroxy or C1-6-alkyloxy.

More specified embodiments of the chemical compounds are stated in claims 2 and 3.

The invention also relates to a pharmaceutical preparation which is characterized in that it contains an antitumor effective amount of a compound of formula I in

combination with one or more pharmaceutically acceptable carriers, excipients, diluents or adjuvants. In order to

inhibit tumors in a mammalian host it is administered to

the mammalian host an antitumor effective amount of a compound of formula I.

The invention thus also relates to the use of the chemical compound for the production of a pharmaceutical preparation for inhibiting tumor growth in a mammal.

In the application, unless otherwise specifically stated, the following definitions apply. The number after the symbol "C" indicates the number of carbon atoms a particular group can contain. E.g. "C 1-6 alkyl" means a straight or branched, saturated carbon chain having from 1 to 6 carbon atoms. Examples are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, sec-pentyl, isopentyl, and n-hexyl.

Depending on the context, "Ci-g-alkyl" can also be the Ci-g-alkylene that forms a bridge between two groups. Examples include propane-1,3-diyl, butane-1,4-diyl, 2-methyl-butane-1,4-diyl, etc. "C2-6~alkenyl" means a straight or branched carbon chain having at least one carbon -carbon double bond and has from 2 to 6 carbon atoms. Examples include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, and hexenyl. Depending on the context, "C2-6-alkenyl" can also be C2-6-endiyl which forms a bridge between two groups. Examples include ethylene-1,2-diyl (vinylene), 2-methyl-2-butene-1,4-diyl, 2-hexene-1,6-diyl, etc. "C2-6-alkynyl" means an unbranched or branched carbon chain having at least one carbon-carbon triple bond and from 2 to 6 carbon atoms. Examples include ethynyl, propynyl, butynyl and hexynyl.

"Aryl" means aromatic hydrocarbon having from 6 to 10 carbon atoms. Examples are phenyl and naphthyl. "Substituted aryl" means aryl independently substituted with from 1 to 4 (but preferably from 1 to 3) groups selected from C1-6 alkanoyloxy, hydroxy, halogen, C1-6 alkyl, trifluoromethyl, C1-6 alkoxy , aryl, C2-6-alkenyl, C1-6-alkanoyl, nitro, amino, C1-6-alkylamino, di-C1-6-alkylamino, as well as amido. "Halogen" means fluorine, chlorine, bromine and iodine.

"Heteroaryl" means a five- or six-membered aromatic ring containing at least 1 and up to 4 non-carbon atoms selected from oxygen, sulfur and nitrogen. Examples of

heteroaryl includes thienyl, furyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, thiadiazolyl, bxadiazolyl, tetrazolyl, thiatriazolyl, oxatriazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl and similar rings.

"Hydroxy protecting groups" include but are not

limited to, ethers, such as methyl, tert-butyl, benzyl, p-methoxybenzyl, p-nitrobenzyl, allyl, trityl, methoxymethyl, methoxyethoxymethyl, ethoxyethyl, tetrahydropyranyl, tetrahydrothiopyranyl, dialkylsilyl ethers, such as dimethylsilyl ether, as well as trialkylsilyl ethers, such as trimethyl silyl ether, triethyl silyl ether and tert-butyl dimethyl silyl ether; esters, such as benzoyl, acetyl, phenylacetyl, formyl, mono-, di- and trihaloacetyl, such as chloroacetyl, dichloroacetyl, trichloroacetyl and trifluoroacetyl; as well as carbonates, such as methyl, ethyl, 2,2,2-trichloroethyl, allyl, benzyl and p-nitro-phenyl.

"Phosphono" means the group -P(0)(0H)2, and "(phosphonooxymethyl)oxy" means the group -OCH2OP(0)(OH) 2-

"Phosphonoprotecting groups" means groups that can be used to block or protect the phosphonofunctional group. Preferably, such protecting groups are those which can be removed by methods which do not appreciably affect the rest of the molecule. Suitable phosphonooxy protecting groups are well known to those skilled in the art, and include e.g. benzyl and allyl groups.

Additional examples of hydroxy and phosphono protecting groups can be found in standard reference works such as Greene and Wuts, "Protective Groups in Organic Synthesis", 2nd ed., 1991, John Wiley & Sons, and McOmie; and

"Protective Groups in Organic Chemistry", 1975, Plenum Press. Methods for introducing and removing protection groups are also found in such textbooks.

"Pharmaceutically acceptable salt" means a metal or amine salt of the acidic phosphono group, where the cation does not contribute substantially to the toxicity or biological activity of the active compound. Suitable metal salts

includes salts 'with lithium, sodium, potassium, calcium, barium, magnesium, zinc and aluminium. Preferred metal salts are sodium and potassium salts. Suitable amine salts are salts with e.g. ammonia, tromethamine (TRIS), triethylamine, procaine, benzathine, dibenzylamine, chlorprocaine, choline, diethanolamine, triethanolamine, ethylenediamine, glucamine, N-methylglucamine, lysine, arginine, and ethanolamine, to name a few.

The term "taxan" or "taxan core" refers to units with the basic structure:

The cyclopropane group which may be formed by R 1 and R 2 in formula I may alternatively be referred to as the "7fi, 81i-methano" group, as in Tetrahedron Letters, vol. 35, No. 43, 1994, p. 7893-7896, or as a "cyclopropa" group as in US Patent 5,254,580. When R<2> and R<6> form a bond, there will of course be a double bond between C<7> and

In compounds of formula I, examples of Rx include methyl, hydroxymethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, chloromethyl, 2,2,2-trichloroethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, ethenyl, 2-propenyl , phenyl, benzyl, bromophenyl, 4-aminophenyl, 4-methyl-aminophenyl, ■4-methylphenyl, 4-methoxyphenyl and the like. Examples of R<4> and R<5> include 2-propenyl, isobutenyl, 3-furanyl (3-furyl), 3-thienyl, phenyl, naphthyl, 4-hydroxy-phenyl, 4-methoxyphenyl, 4-^f fluorophenyl, 4-trifluoromethylphenyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl^ tert-butyl, ethenyl, 2-propenyl, 2-propynyl, benzyl, phenethyl, phenylethenyl, 3,4-dimethoxyphenyl , 2-furanyl (2-furyl), 2-thienyl, 2-(2-furanyl)ethenyl, 2-methylpropyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl and the like.

The compounds having the ■general formula I exhibit a significant inhibitory effect against abnormal cell proliferation, . and has therapeutic properties that make it possible to treat patients who have pathological conditions associated with abnormal cell proliferation. The pathological conditions include the abnormal cell proliferation of malignant or non-malignant cells in various tissues and/or organs, such as muscle, bone and/or connective tissue; the skin, brain, lungs and genitals; the lymphatic and/or renal system; breast cells and/or blood cells; the liver, digestive system and pancreas, as well as the thyroid and/or adrenal glands. These pathological conditions may also include psoriasis; solid tumors; ovarian, breast, brain, prostate, bowel, stomach, kidney and/or testicular cancer; Karposi's sarcoma; cholangiocarcinoma; choriocarcinoma, neuroblastoma; ■ Wilm's tumor; Hodgin's disease; melanoma; multiple myeloma; chronic lymphocytic leukemia; as well as acute or chronic granulocytic lymphoma. The compounds according to the invention are particularly useful in the treatment of non-Hodgin's lymphoma, multiple myeloma, melanoma and ovarian and urothelial, oesophageal, lung and esophageal cancer. The products according to the invention can be used to prevent or delay the appearance or recurrence or to treat these pathological conditions.

The compounds according to the invention can be prepared by methods known from conventional organic chemistry. Reaction scheme I, which shows a method for preparing compounds with the formula I, is only shown as an illustration and is not to be regarded as limiting the methods for preparing the compounds by other methods.

The "acid" of a compound of formula II is any acid capable of controlling the C'3-amino group. Examples of acid salts include salts formed

with mineral acids, such as HC1, H2SO4 or HNO3, or with organic acids, such as trifluoroacetic acid, acetic acid, p-toluenesulfonic acid, methanesulfonic acid, etc. Step (a) comprises liberation of the C3'-amino group with base, followed by reaction of the liberated amino group with a compound of the formula III, where R^<3> and R<14> independently of each other are C1-6-alkyl, aryl, substituted aryl or phosphono-protecting group. The base can be any base for neutralizing the aminoprotonating acid and which also functions as an acceptor of protons formed during the reaction between the amine and chloroformate of the formula III. Examples of preferred bases include inorganic bases or organic bases, such as diisopropylethylamine, triethylamine, pyridine, dimethylaminopyridine, etc.

When r<!3> and/or r<!4> is a phosphono-protecting group, it is removed in step (b) to produce further compounds of formula I.

Reaction scheme I

The preparation of compounds of formula II is well described in PCT patent application WO 94/14787, which was published on July 7, 1994. Briefly, they are prepared by steps which include:

(a) coupling of the oxazoline of formula V

with the C 1 -hydroxy of the taxane of formula VI to form a compound of formula VII

and

(b) contacting a compound of formula VII with an acid capable of opening the oxazoline ring in the compound of formula VII to form a compound of formula II or a salt thereof.

Oxazolines of formula V are already well described in PCT patent application WO 94/14787, which was published on July 7, 1994.

In formulas II, III, V, VI and* VII above, p, R^,

R1, R2, R2', R3, R4, R5, R6, R6', R7, R<7>', R<8> and R<9> as indicated above.

Many publications are now known which teach how paclitaxel taxane core substituents can be converted to other moieties. To use these established methods or close variants thereof, taxanes of the formula VI can be easily prepared. When it e.g. applies to the transformation of C4-acetoxy into other functional groups, see S.H. Chen et al., J. Organic Chemistry, vol. 59, 1994, pp. 6156-6158, and PCT Patent Application WO 94/14787, which was published on July 7, 1994. For the conversion of C 2 -benzoyloxy to other

groups, please refer to S.H. Chen et al., Biorganic and Medicinal Chemistry Letters, vol. 4, No. 3, 1994, pp. 479-482, and European Patent Application 617,034 A1, published September 28, 1994. For modification of C10-acetyloxy see J. Kant et al., Tetrahedron Letters, vol. 35, No. 31, 1994, pp. 5543-5546, and CIS Patent 5,294,637. For the preparation of CIO and/or C7 unsubstituted (deoxy) derivatives, reference is made to European Patent Application 590,267 A2, published April 6, 1994, and PCT Patent Application WO 93/06093, published April 1, 1993. For the preparation of 715,8B- methano-, 6a, 7a-dihydroxy and 6,7-olefin groups, reference is made to R.A. Johnson, Tetrahedron Letters, vol. 35, No. 43, 1994, pp. 7893-7896, US Patent 5,254,580 and European Patent Application 600,517 A1, published June 8, 1994. For the preparation of C7/C6 oxirane, reference is made to X. Liang and G.I. Kingston, Tetrahedron Letters, vol. 36, No. 17, 1995, pp. 2901-2904. For the preparation of C7-epi-fluorine, reference is made to G. Roth et al., Tetrahedron Letters, vol. 36, (1993) pp. 1609-1612. For the production of C7 esters and carbonates, reference is made to US Patent No. 5,272,171 and S.H. Chen et al., Tetrahedron, vol. 49, No. 14, 1993, pp. 2805-2828. For 9a- and 911-hydroxytaxanes, reference is made to L.L. Klein, Tetrahedron Letters, vol. 39, No. 13, pp. 2047-2050, PCT Patent Application WO 94/08984, published April 28, 1994, US Patent 5,352,806, and PCT Patent Application WO 94/20485, published September 15, 1994.

The specific examples that follow illustrate the preparation of the compounds according to the invention. The method can be adapted to variations for the production of compounds according to the invention which are not specifically described. Variations of the method after preparing the same compound in a slightly different way will also be obvious to those skilled in the art.

In subsequent experiments, all temperatures are in °C unless otherwise stated. The nuclear magnetic resonance (NMR) spectral characteristics refer to chemical shifts (8), expressed in parts per million (ppm) in relation to tetramethylsilane (TMS) as a reference standard. The relative area that is reproduced for the different shifts in proton NMR spectral data corresponds to the number of hydrogen atoms of a particular functional type in the molecule. The nature of the shifts' in terms of multiplicity is indicated as broad singlet (bs or br s), broad doublet (bd or br d), broad triplet (bt or br t), broad quartet (bq or br q), singlet (s) , multiplet (m), doublet (d), quartet (q), triplet (t), doublet of doublet (dd), doublet of triplet (dt), as well as doublets of quartet (dq). The solvents used for recording NMR spectra are acetone-dg (deuterated acetone), DMSO-dg (perdeuterodimethylsulfoxide), D2O (deuterated water), CDCI3 (deuterochloroform), as well as other conventional deuterated solvents. The infrared (IR) spectral description includes only absorption wavenumber (cm-<1>), which has value as identification of functional group.

"Celite" is a registered trademark of Johns-Manville Products Corporation for diatomaceous earth.

The abbreviations used here are conventional abbreviations that are widely used in the field. Some of these are: DAB (deacetylbaccatin-III), MS (mass spectroscopy), HRMS (high resolution mass spectroscopy), Ac (acetyl), Ph (phenyl), v/v (volume/volume), FAB (fast atom bombardment), NOBA (m-nitrobenzyl alcohol), min [minute(s)], h [hour (s) ], *0C (tert-butoxycarbonyl), CBZ or Cbz

(benzyloxycarbonyl), Bn (benzyl), Bz (benzoyl), Troe (2,2,2-trichloroethyloxycarbonyl), DMS (dimethylsilyl), TBAF (tetrabutylammonium fluoride), DMA? (4-dimethylarinopyridine), TES (triethylsilyl), DMSO (dimethyl sulfoxide), THF (tetrahydrofuran), HMDS (hexamethyldisilazane), MeOTf (methyl triflate).

1. Preparation of O-chloromethyl-S-butyl carbonothioate

Preparation of O-chloromethyl-S-butylcarbonothioate was carried out by the method described by M. Folkman and F. Lund in "Synthesis", 1990, -p. 1159. 16.0 ml (200 mmol). Butanethiol was added dropwise to a solution of sodium methoxide in methanol (43 mL, 200 mmol, 25% by weight, Aldrich), which had been cooled to 0°C, and the resulting mixture was stirred for 2 h. The reaction mixture was then concentrated in vacuo and the remaining solid suspended in 300 ml of anhydrous ethyl ether. The heterogeneous solution was then cooled to -78°C, and a solution of 17.6 mL (200 mmol) of chloromethyl chloroformate in 70 mL of ether was added dropwise over 40 minutes. The resulting solution was stirred at -78°C for an additional 2 hours, and the reaction mixture was then warmed to room temperature and stirred for 13 hours. The reaction mixture was then suction filtered using a pad of Celite, the collected salts were washed with ether, and the filtrate was concentrated in vacuo. The resulting residual oil was purified by fractional distillation (boiling point 103-107°C, house vacuum 25-30 mbar, boiling point according to the literature 99-101°C, 24 mbar). A middle fraction yielded 18 g (52% yield) of the desired O-chloromethyl-S-butylcarbonothioate.

1H NMR (300 MHz, CDCl 3 ) δ 5.72 (2H, s), 2.90 (2Hr dd, J = 8.7, 8.7 Hz), 1.63-1.51 (2H, m) , 1.45-1.31 (2H, m), 0.91-0.82 (3H, m).

2. Preparation of O-iodomethyl-S-butyl carbonothioate

A solution of 10.0 g (0.054 mol) of O-chloromethyl-S-butylcarbonothioate in 10 mL of acetone was added to a solution of 16.4 g (0.108 g, 2 equivalents) of sodium iodide and 0.461 g (0.0054 mol, 0.1 equivalent) of sodium bicarbonate in 200 ml of acetone at room temperature. The reaction mixture was then heated to 45°C and stirred for 2 hours. At this point, a sample of reaction- . the mixture concentrated in vacuo and the remaining oil examined by 1 H NMR, which showed consumption of starting material and formation of a single product. The remaining reaction mixture was then filtered using a pad of Celite and the filtrate concentrated in vacuo. The remaining oil was then partitioned between water and pentane, and the organic layer was washed with aqueous solutions of 5% sodium bicarbonate, 1% sodium thiosulphate, and brine. The aqueous layers were back-extracted with pentane, and the combined organic solutions were dried over sodium sulfate and concentrated in vacuo. The resulting residual oil was purified by NMR analysis and the desired O-iodomethyl-S-butylcarbonothioate was used without further purification. <3->H NMR (300 MHz, CDCl3) δ 5.93 (2H, s, observed shift from corresponding chlorine compound), 2.83 (2H, dd, J = 8.7, 8.7 Hz), 1, 62-1.51 (2H, m), 1.48-1.36 (2H, m), 0.92-0.84 (3H, m). 3. Preparation of tetrabutylammonium dibenzyl phosphate salt 15.0 (0.054 mol) of dibenzyl phosphate was added to a solution of tetrabutylammonium hydroxide (40% by weight in water, Aldrich, 35.0 g, 0.054 mol) in water at room temperature, and the resulting homogeneous solution was cooled in a bath of dry ice and acetone until solidification was complete. Removal of water by lyophilization afforded the desired salt as a viscous oil, which was used without further purification. 4. Preparation of O-dibenzylphosphonooxymethyl-S-butyl carbonthioate

A solution of crude O-iodomethyl-S-butylcarbonothioate (0.054 mol) in 20 mL of THF was added to a solution of 28.5 g (0.054 mol) of tetrabutylammonium dibenzyl phosphate in 150 mL of THF at room temperature, and the resulting mixture was stirred for 24 hours . The reaction mixture was then filtered using a pad of Celite and the filtrate was concentrated in vacuo. The remaining oil was purified by flash chromatography (eluted with hexanes/ethyl acetate), from which a middle fraction afforded 10.0 g (42.5% yield) of the desired O-dibenzylphosphonooxomethyl-S-butyl carbothioate as a pale yellow oil. .

1H NMR (300 MHz, CDCl 3 ) δ 7.34 (10H, brs), 5.62 (2H, d, J = 14.0 Hz), 5.05 (4H, d, J = 7.8 Hz), 2.82 (2H, dd, J = 7.3 Hz), 1.62-1/51 (2H, m), 1.41-1.30 (2H, m), 0.89 (3H, dd, J = 9.4 Hz).

5. Preparation of O-dibenzylphosphonooxomethyl chloroformate

1.29 mL (0.0160 mol, 1.2 equivalents) of distilled sulfuryl chloride was added in one portion to a solution of 5.7 g (0.0134 mol, 1.0 equivalents) of the O-dibenzylphosphonooxymethyl-S-butylcarbonothioate in dichloromethane cooled to

-40°C. The reaction mixture was stirred at this temperature for 20 minutes. At this point the cooling bath was removed and the reaction mixture was warmed to room temperature and stirred for 3 hours. The reaction mixture was then concentrated in vacuo and the remaining oil subjected to high vacuum to remove byproducts from the reaction and any remaining sulfuryl chloride. ^H NMR analysis of

the crude chloroformate showed cs. 60% conversion of the starting material -O-dibenzyl phosphonooxymethyl-S-butylcarbonothioate to the corresponding chloroformate, which was used without further purification in the subsequent conversion. -N NMR, selected resonances for chloroformate (300 MKz, CDCl3) 6 5.59 (2H, d, J = 14.0 Hz), folded shift relative to the corresponding thiocarbonate), 5.10 (4H, d, J = 1.8 Hz, recorded shift in relation to the corresponding thiocarbonate). 6. Preparation of N-deben2oyl-M-{[(dibenzylphosphonooxymethyl]oxy}carbonyl-2'-O-benzoylpaclitaxel (Ia)

To a solution of the chloroformate (ca. 0.0080 mol, 1.7 equivalents at 60% conversion) in dichloromethane cooled to 0°C was added 4.7 ml (0.0208 mol, 5 equivalents) of diisopropylethylamine followed by 4, 0 g (0.00449 mmol) of N-debenzoyl-2'-O-benzoylpaclitaxel hydrochloride (Ila). An additional 4.7 mL (0.0208 mol) of diisopropylamine was then added, the cooling bath was removed, and the reaction mixture was warmed to room temperature and stirred for an additional 1.5 h. The reaction mixture was then diluted with ethyl acetate and the reaction quenched by the addition of saturated aqueous sodium bicarbonate. The organic layer was then removed and washed with a saturated aqueous ammonium chloride solution followed by brine. The aqueous layers were then back-extracted with ethyl acetate, and the combined organic layers were dried over sodium sulfate and concentrated in vacuo to give a pale yellow oily solid. Purification of the crude solid by flash chromatography (eluted with hexane/ethyl acetate) afforded 2.9 g (55% yield) of the desired dibenzyl phosphate as a white solid.

<!>h NMR (300 MHz, CDCl 3 ) δ 8.19-8.11 (2H, m), 7.98-7.89 (2H, m), 7.61-7.18 (21H, m) , 7.10-7.07 (1H, m), 6.43 (1H, dd, J = 8.6-8.6 Hz), 6.12 (1H, d, J = 9.9 Hz), 5.78-5.61 (4H, m), 5.18 (1H, dd, J = 5.2 Hz, 14.2 Hz), 5.01-4.92 (2H, m), 4.75 -4.55 (2H, m), 4.51-4.42

<1H, m), 4.31-4.27 (2H, m), 3.86 (1H, d, J = 7.2 Hz), 3.62 (1 Hz, brs), 2.67-1 .65 (16H, m including singlets at 2.51, 2.23, 2.01 and 1.22, 3H each), 1.21 (3H, s), 1.15 (3H, s); mass spectrometry (M + Na <+>) 1210. 7. Preparation of N-debenzoyl-N-[(phosphonooxymethyl)-■

6kysy] carbonyl- 2'- O- benzoylpaclitaxel ( Ib)

200 mL of ethyl acetate was added to 3.0 g of 10% palladium-on-carbon in a Parr hydrogenation vessel. A solution of 2.9 g (0.0024 mol) of N-debenzoyl-N-{[(di-benzylphosphonooxy)methyl]oxy}carbonyl-21-0-benzoylpa.cli-taxel (Ia) in 50 ml acetyl acetate was then added, and the reaction vessel was connected to a Parr hydrogenation apparatus. The reaction mixture was then evacuated for approx. 1 minute using house vacuum and then

pressurized with hydrogen gas to approx. 3.5 kg/cm^. This procedure was repeated three times, after which the reaction container was kept at approx. 3.5 kg/cm<2> and shaken for 12 hours. The reaction mixture was then filtered using a sintered glass funnel (fine porosity), and during this process approx. 50 ml of methanol added to completely dissolve the phosphate-free acid and facilitate filtration. A sample of the filtrate that contained the pro-drug

was concentrated in vacuo and analyzed by high pressure liquid chromatography (85% purity observed). The remaining filtrate was then added to a solution of triethanolamine in ethyl acetate (0.1 M, 23 mL, 0.0023 mol, 0.95 equivalent), and the resulting solution was concentrated in vacuo. The crude prodrug salt was purified by medium pressure C18 chromatography. In this process, the crude phosphatamine salt was taken up as a suspension in 5% acetonitrile in water (50-80 ml) and added to the C18 column (equilibrated with 5% acetonitrile in water). A gradient elution was used (5% acetonitrile, 95% water, 10%:90%, 15%:85%, 20%:80%, 25%:75%, 30%:70%), and fractions containing compound (Ib) (>95% purity by high pressure liquid chromatography) was combined and concentrated in vacuo to remove acetonitrile. The remaining aqueous solution of compound Ib was then frozen and water was removed by lyophilization to give 1.34 g (51% yield) of compound Ib as a bright white solid.

<3->H NMR (300 MHz, CD30D:CDCl3 ca. 2:1, v/v)) δ 8.11-8.02 (4H, m), 7.66-7.35 (11H, m) , 7.24 (1H, dd, J= 7.2-7.2 Hz), 6.24 (1H, dd, J = 8.7, 8.7 Hz), 5.65-5.43 (5H , m), 4.97 (1H, d, J = 8.4 Hz), 4.37 (1H, dd, J= 6.5, 10.7 Hz), 4.25-4.19 (2H, m) , 3.85-3.79 (7H,

■m), 3.33-3.29 (6H, m), 2.54-1.66 (16H, m, containing singlets at 2.49, 2.16, 1.97 and 1.66, 3H each ), 1.18 (3H, s), 1.13 (3H, s);

mass spectrometry (M-l) 1006 (conformity).

By following largely the same methods as described above, the following compounds according to the invention can be prepared.

The compound with formula I according to the invention is an effective tumor-inhibiting agent and applicable in human and/or veterinary medicine. For example are effective in the treatment of tumors in an in vivo study as described in EP patent application 604,910 A1, published July 6, 1994. In one test, in Balb/c x DBA2F^ (CDFi) hybrid mice implanted subcutaneously 0.1 ml of a 2% (w/v) slurry of M109 lung carcinoma (as described in W. Rose, "Evaluation of Madison 109 Lung Carcinoma as a Model for Screening Antitumor Drugs", "Cancer Treatment Reports", vol. 65, Nos. 3-4, 1981, pp. 299-312. The test compounds and the reference drug, paclitaxel, are administered intravenously to groups of mice. Each group receives a compound at a different dose level, and three or four different dose levels are evaluated per The test compounds are also evaluated orally in a similar way.

Mice are followed daily for survival until they die, or approx. 90 days after tumor implantation, whichever occurs first. One group of mice per trial remains untreated and functions as a control. Tumors are also measured once or twice a week, and the size in mm is used to estimate tumor weight in accordance with the published method (ibid). Mean survival times of mice (T) treated with compound are compared with mean survival times of parallel control mice (C). The ratio of the two values for each compound-treated group of mice is multiplied by 100 and expressed as a percentage (ie, % T/C). Also, the average time for the treated groups and for the control group for the tumor to grow to 1 g, expressed as T-C values, in days is determined. The greater the T-C value, the greater the delay in primary tumor growth. Compounds exhibiting % T-C > 1.25% and/or T-C > 4.0 days are considered to be active in this M109 SC model.

Compound Ib (as triethanolamine salt) was evaluated

in accordance with the above protocol. In one test, when administered intravenously in the dose range of 20-45 mg/kg/injection given once daily for five days beginning on day 4 after tumor implantation, it had T/C values of 132

from 145% and T-C values of from 8.8 to 14.0. When the compound was given orally in an amount of 200-400 mg/kg/administration once daily for five days beginning on day 4 after tumor implantation, it had T/C values of from 132 to 179% and T-C values of from 10.5 to 24.3 days.

Thus, for the inhibition of tumors in humans and/or other mammals, an antitumor-effective amount of the compound of formula I is administered to a tumor-bearing host.

For the treatment of various tumors, the compound of formula I according to the invention can be used in a similar way to paclitaxel, see e.g. Physician's Desk Reference, 49th ed., Medical Economics, p. 682, 1995. The dosage, administration method and schedule of the compound of the invention are not particularly limited. An oncologist skilled in the art of cancer treatment will be able to find, without undue experimentation, an appropriate treatment protocol for administering the compound of the invention. Thus, the compound of formula I may be administered in any suitable manner, parenterally or orally. Parenteral administration includes intravenous, intraperitoneal, intramuscular and subcutaneous administration.

The doses used to carry out the methods according to the invention are those which make it possible - to administer prophylactic treatment or to produce a maximum therapeutic response. The doses vary, depending on the type of administration, the particular compound chosen and the personal characteristics of the individual being treated. In general, the doses are those that are therapeutically effective for the treatment of disorders caused by abnormal cell proliferation. The compound according to the invention can be administered as often as necessary to achieve the desired therapeutic effect. Some patients may respond quickly to relatively high or low doses, and then require a medium maintenance dose or no maintenance dose at all. For intravenous administration, the doses can e.g. be in the order of magnitude from 20 to 500 mg/m<2> during from 1 to 100 hours. For oral administration, the dosage can be in the range from 5 to 1000 mg/kg/day of body weight. The actual dose used will vary with the particular preparation being formulated, the method of administration and the particular site, the particular host and type of tumor being treated. Many factors that modify the effect of the medicine will be taken into account when it comes to determining the dosage, such as the patient's age, weight, sex, diet and physical condition.

The invention also relates to pharmaceutical preparations containing an antitumor effective amount of compound I in combination with one or more pharmaceutically acceptable carriers, excipients, thinners or adjuvants. The preparations can be prepared by conventional methods. Examples of formulation of paclitaxel or derivatives thereof can be found e.g. in US Patents 4,960,790 and 4,814,470, and such examples can be followed to formulate the compound of the invention. E.g. the compound of formula I can be formulated in the form of tablets, pills, powder mixtures, capsules, injections, solutions, suppositories, emulsions, dispersions, mixed in foodstuffs, as well as in other suitable forms. It can also be produced in the form of sterile, solid preparations, e.g. freeze-dried, and if necessary combined with other pharmaceutically acceptable excipients. Such solid preparations may be reconstituted with sterile water, physiological saline, or a mixture of water and an organic solvent, such as propylene glycol, ethanol and the like, or another sterile injectable medium immediately prior to use for parenteral administration.

Typical pharmaceutically acceptable carriers are e.g. mannitol, urea, dextrans, lactose, potato and corn starches, magnesium stearate, talc, vegetable oils, polyalkylene glycols, ethyl cellulose, poly(vinyl)pyrrolidone, calcium carbonate, ethyl oleate, isopropyl myristate, benzyl benzoate, sodium carbonate, gelatin, potassium carbonate, silicon acid. The pharmaceutical preparation can also contain non-toxic auxiliary substances, such as emulsifiers, preservatives, wetting agents and the like, e.g. sorbitan monolaurate, triethanolamino oleate, polyoxyethylene monostearate, glyceryl tripalmitate, dioctyl sodium sulfosuccinate and the like.

Claims (6)

1. Chemical compound, characterized in that it has the formula ■(!) or a pharmaceutically acceptable salt thereof characterized by ar R<1> is hydroxy, -CO(0)R<x> or -OC(0)OR<x>, R<2> is hydrogen, hydroxy, -OC(0)R<X> or -OC(0)OR<s>, R<2>' is hydrogen, hydroxy or fluorine, r<6>" is hydrogen or hydroxy, R^ is hydrogen, or R<2> and R^ can together form an oxirane ring or a bond, R<3> is hydrogen, hydroxy, C1-6-alkyloxy, -OCO<N>R^R<12,><->QC(0)Rx or -OC(0)ORx, R<8> is methyl or hydroxymethyl, or R^ and R2- can together form a cyclopropane ring, R<9> is hydroxy or -OC(0)R<x>, below those preceding statements that r<8> and R<2> form a cyclopropane ring, R<2>' is hydrogen; when R<2> and R*> form oxirane ring or dob— belt bond, R<2>' and R^<1> are hydrogen; when R<2> is hydroxy, -OC{0)R<x> or -OC<O)0R<x>, R<2>' is hydrogen; and. when R<2>' is fluorine, R<2> is hydrogen, one of R<7> and R<7>' is hydrogen and the other is hydroxy, -OC(0)Rx or -OC(0)OR<x>, or R<7> and R<7>' can together form an oxo group, R^-1 and R^-2 are independently C 1-6 alkyl, hydrogen, aryl or substituted aryl, R<4> and R° are independently of each other C]__g-alkyl, C2-g-alkenyl/C^-g-alkynyl or -Z-R<10>, where 2 is* a direct bond, C]__g-alkyl or C2-g-alkenyl, and R-° is aryl, substituted aryl, C1-g-cycloalkyl or heteroaryl, p is 0 or 1, R°^ and R e are independently hydrogen, C 1-6 alkyl, aryl, substituted aryl or phosphono-protecting group, R 1 is hydrogen or hydroxy, Rx is C3-5-cycloalkyl, C2-g-alkenyl or C1-g-alkyl, all of which are optionally substituted with from 1 to 6 identical or different halogen atoms, or Rx is a radical with the formula where D is a bond or C1_g-alkyl, and "Ra, RD and Rc are independently hydrogen, nitro, amino, C1_g-alkylamino, di-C1_g-alkylamino, halogen, C1_g-alkyl, hydroxy or C 1-6 alkoxy. 2. Compound according to claim 1, characterized in that R- is -CO{0)R<x>; R<2> is hydroxy; R<2>' is hydrogen; R<3> is hydroxy or -OC(0)Rx; R 8 is meryl; R₁ and R₁' are hydrogen; R<9> is -OC(0)Rx; R7 and r7' together form an oxo group; R^ and R^ are independently C 1-6 -alkyl, C 2-6 -alkenyl or -Z-R<1>^ where Z is a direct bond or C 1-6 alkyl and R<1®> is aryl, substituted aryl, C 3-6 cycloalkyl or heteroaryl; p is 0; R 1 and R 6 are hydrogen; R<r> is hydrogen, Rx is C3_g-cycloalkyl, C2-g-alkenyl or C]_g-alkyl, where all are optionally substituted with from 1 to 6 identical or different halogen atoms, or Rx is a radical of the formula where D is a bond or C 1-6 alkyl, and Ra, PP and R<c> are independently hydrogen, nitro, amino, C 1-6 alkylamino, di-C 1-6 alkylamino, halogen, C 1-6 alkyl or C 1 -C 6 -Alkoxy. 3. Compound according to claim 2, characterized in that it is N-debenzoyl-N-[(phosphonooxy-methyl)oxy]carbonyl-2<1->O-benzoylpaciitaxel. 4. The triethanolamine salt of the compound according to claim 3. 5. Pharmaceutical preparation, characterized in that it comprises an anti-tumor effective amount of a compound according to claim I and a pharmaceutically acceptable carrier. 6. Use of a compound according to claim 1, for the production of a pharmaceutical preparation for inhibiting tumor growth in a mammal. 1. Use in accordance with claim 6, where the pharmaceutical preparation is for oral administration.